The invention relates to a piston and cylinder unit and more particularly so such an arrangement of the type comprising a cylinder tube shut off at both its ends by cylinder end caps and a piston running axially in the cylinder tube with a piston rod extending from it in the longitudinal direction of the cylinder tube through at least one of the cylinder end caps so that it may slide therethrough, with a fluid tight sealing effect, for the operation of a load situated outside the cylinder tube.